Swivel nozzle



Aug. 14, 1962 J. F. GEARY, JR

SWIVEL NOZZLE Filed Oct. 16, 1959 INVENTOR. JOSEPH F. GEARXJR.

I ATTORNEYS.

Patented Aug. 142, 1962 3,048,977 SWIVEL NOZZLE Joseph F. Gear-y, Zita,Everett, Mass assignor to the United States of America as represented bythe Secretary of the Navy Filed Oct. 16, 1%9, Ser. No. 847,024 3 Claims.(Cl. 6tl35.55) (Granted under Title 35, US. Code (1952), see. 266) Thisinvention may be manufactured and used by or for the Government of theUnited States of America for governmental purposes without the paymentof any royalties thereon or therefor.

This invention relates to the control of missiles; more particularly itrelates to a movable nozzle for the control of missiles by deflectingthe exhaust gases from the reaction engines thereof.

Such control has been achieved in the past with the use of moveableexternal control surfaces and by deflecting the exhaust gases with jetvanes, jetevators, and gimballed nozzles. Such methods possessdisadvantages however in certain applications.

External control surfaces, besides being bulky, do not allow precisecontrol in the initial stages of flight since the velocity of themissile is low and the amount of control attainable from such surfacesis a function of missile velocity. The use of jet vanes results inlessened thrust of the engine due to the losses associated with the dragof the vanes in the exhaust and the turbulence in the exhaust flowcreated by the vanes; the use of jetevators also results in lessenedthrust of the engine due to the losses associated with theunderexpansion of and the turbulence in the exhaust. Additionally, theuse of both jet vanes and jetevators has control limitations.

Gimballed nozzles have the ability to deflect the exhaust gases in aninfinite number of planes and so control the pitch and yaw of themissile but the roll of the missile must be controlled by other means.

Moveable nozzles present problems in achieving gas tight seals betweenthe moveable and stationary parts to prevent leakage. Such seals havebeen achieved in the past, with varying degrees of success, bymaintaining extremely close clearances between the moving parts or bythe use of flexible diaphragms. The former expedient requires extensivemachining and the parts are quite susceptible to binding due to unequalthermal expansions or to the build-up of combustion products on the twoadjacent surfaces; the latter requires materials which will not breakdown when subjected to the fiexure, temperature, and pressureencountered in such an application.

It is therefore a general object of the present invention to provide avariable position nozzle arrangement wherein undesired leakage of theexhaust gases is prevented to an exceptionally high degree, while at thesame time, allowing for unequal thermal expansion of various portions ofthe assembly, thereby preventing seizure of the relatively movable partsof the system.

It is also an object of this invention to provide a new and improvedmoveable nozzle with which the direction of the thrust of a reactionmotor can be controlled.

Another object is to provide new and improved means whereby a jetpropelled missile can be completely controlled in roll, pitch, and yaw,at all velocities.

A further object is to provide improved sealing means between themoveable and the stationary parts of the nozzle so as to prevent gasleakage therebetween.

The invention will be best understood from a consideration of thefollowing detailed description taken in connection with the accompanyingdrawing, with the understanding, however, that the invention is notconfined to a strict conformity with the showing of the drawing but maybe changed or modified so long as such changes or modifications mark nomaterial departure from the salient features of the invention asexpressed in the appended claims.

FIG. 1 is a perspective view of the rear portion of a rocket motorhaving four nozzles of the instant type; and

FIG. 2 is an elevational view, partly in section and broken away, of oneof the nozzles of FIG. 1.

Referring now to the drawing wherein like reference characters designatelike or corresponding parts through out the several views, FIG. 1illustrates. a rocket motor having an outer casing 11, an end closure 2,and nozzles 3, 4, 5, and 6 mounted therein with the weight distributionthereof being symmetrical with respect to the axis of the motor.

Referring now to FIG. 2, there is shown a portion of closure 2containing nozzle 5 which is identical to each of the other nozzles 3,4- and 6. Closure 2 is shown to be provided with an exhaust port 35which opens into an annular recess 36 in which is inserted a mainbearing housing 10 having 0 ring 11 forming a seal between closure 2 andmain bearing housing 11). Closure 2 is further provided with a pluralityof tapped bores 37 which are arranged in a pattern around recess 36.Housing 10 is provided with a flange 12 which abuts the outer surface ofend closure 2 when housing 1& is positioned in recess 36. Flange 12 hasa plurality of apertures corresponding to and in alignment with saidtapped bores 37 in end closure 2 and threaded bolts 13 pass through theapertures in the flange and engage the threads in tapped bores 37 thussecuring housing 10 to end closure 2.

Annular insert housing 14 is closely fitted within main housing 10 andis secured therein by means of threaded lock ring 16 which engagesthreads 38 of main housing 16. Suitable bores 39 may be provided in lockring 16 to receive a torque tool (not shown) whereby ring 16 may besecurely tightened in position. In addition to its locking function, itwill be noted that lock ring 14 also serves to provide a tortuous pathfor any exhaust gas which attempts to pass between insert housing M andmain housing 10 and, in addition, annular seal ring 15 may be providedto increase sealing between the two housing portions. It will beapparent that internal surface 33 of insert housing 1% and internalsurface 34 of main housing 10 together form a portion of a sphere, thepurpose of which will hereinafter be made more clearly apparent.

Main housing 16 is further provided with two diametrically disposedenlarged portions 40 which act as journal boxes for bearings 17 anddiametrically disposed shafts 18, the latter of which have a common axisnormal to the axis of housing 10. Shafts 18 are radially secured inbearings 17 by rings '19 and 21 which are positioned in annular groovesin the outer ends of shafts 18. Caps 22 form closures for journal boxes4% and may be conveniently secured thereto by means of screws 23 andsealed by 0 rings 24 set in suitable sealing grooves.

spasm? Shafts 18 extend radially inwardly from main housing It) throughsuitable apertures 42 and are secured to spherical portion 4 1 of nozzle30, as for example, by force fitting in blind bores 43. In this manner,nozzle 30 is pivotally supported within main housing 10 by means ofshafts 18 and bearings 17, and spherical portion 41 of nozzle 30 is freeto oscillate within the spherical cavity provided by surfaces 33 and 34.It should also be noted that relatively greater clearance is providedbetween surfaces 32 and 33 than is provided between surfaces 32 and 34.This unequal clearance is provided in order to allow for unequal thermalexpansion of surfaces 32, 33 relative to surfaces 32, 34 which occursdue to the closer proximity of surfaces 32, 33 to the hot gas flow thanthat of surfaces 32, 34 which are relatively farther removed therefrom.In addition, it will also be apparent that surfaces 32, 34 are muchcloser to the external surfaces of housing 40 and spherical portion 41which are in contact with the much cooler ambient atmosphere, and also,annular split metal ring seal 25 serves to greatly reduce the amount ofhot gas which reaches surfaces 32, 34. Furthermore, O ring seal 26substantially eliminates the residual leakage through seal 25 frompassing any farther which thus builds up a back pressure to the left ofO ring 26 as viewed in FIG. 2 which, in turn, substantially reducesfurther leakage through seal 25.

It will therefore be apparent that the disclosed nozzle assemblyachieves maximum temperature compensation for each of the relativelymovable surface portions and thereby solves the problem of excessivefrictional engagement between all movable surfaces, While at the sametime, solving the problem of exhaust leakage between the movablesurfaces. Even more importantly, the subject invention greatly reducesthe heretofore required machining tolerances of surfaces 32, 32, 33 and34 since nozzle 30 is supported by shafts 18 journaled in externallylocated bearings 17 which is entirely different from the bearing designheretofore employed in so-called gimbal mounted nozzles.

Nozzle piece 30 is shaped cylindrically externally for a short distancebehind the spherical end portion and collar 27 fits about the nozzlethereat, gripping it tightly. Arm 28 is attached to said collartangentially and extends outwardly.

Rod 29 is attached normally to arm 28 near the outward end thereof, theother end of rod 29 being attached to conventional power and sensingmeans, not shown.

Insert 31 is an annular member which is cylindrically shaped externallyand fits within a corresponding indentation in nozzle piece 30.

It is also apparent that a considerable thickness of material liesbetween the inner surface of nozzle piece 30 and O ring 26. Thisthickness of material is designed to act as a heat sink so as tominimize the heating of O ring 26 as well as surfaces 32, 34 andbearings 17.

The internal configuration of the nozzle is dictated by conventionaldesign criteria, and the materials employed in its construction areconventional and well known in the art.

Ball bearings are preferred but other types may be used. The amount ofangular movement in the joint is a function of the size of the ball andsocket.

Ring 25 and O ring 26 may be located at any convenient place, providedonly that ring 25 be placed ahead of the ring and that a considerablethickness of material be present between the inner surface of the nozzleand the said O ring.

To completely control the roll, pitch, and yaw of a missile, it isnecessary to utilize four of the instant nozzles. Each pair ofoppositely disposed nozzles must rotate in the same direction,simultaneously or separately, as the case may be. For example, nozzles 3and would rotate in a horizontal plane about vertical axes and nozzles 4and 6 would rotate in a vertical plane about horizontal axes, as viewedin FIG. 1. When the four nozzles are arranged in a missile as aforesaid,and rod 29 of each nozzle is connected to suitable power and sensingmeans, it is possible to vary the direction of the thrust of each nozzlein such a fashion that complete control of the roll, pitch, and yaw ofthe missile is obtained.

From the foregoing it will be apparent that a swivel nozzle structurehas been provided which is suitable for use in the complete control ofthe flight of jet propelled missiles. The sealing means herein providedis an improvement over previous sealing means in that a ring similar toa conventional piston ring is interposed between the exhaust gases andthe 0 ring which forms the primary seal, and in that the O ring isfurther protected by the use of a heat sink to reduce the amount of heatconducted to the ring through the walls of the nozzle.

While the preferred embodiment of the invention has been shown, it willbe obvious to those skilled in the art that the invention is not solimited but is susceptible of various other changes and modificationswithout departing from the spirit thereof.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:

1. A high temperature, high pressure, variable position nozzle assemblyfor directing the flow of high temperature and high pressure fiuidscomprising; annular bearing housing means having an internal surfacedefining a spherical cavity, a discharge nozzle having a partlyspherical external surface portion positioned within said sphericalcavity, bearing means positioned in said bearing housing meansexternally of said nozzle, supporting shaft means journaled at one endin said bearing means and connected at the other end to said nozzlewhereby said nozzle is supported for pivotal oscillation in one plane,means for compensating for unequal thermal growth of said surfacescomprising a thermal expansion gap positioned between said sphericalsurfaces on one side of said supporting shaft means to absorb theunequal thermal expansion of said surfaces, a first seal means locatedwithin said gap and partially sealing said surfaces against hightemperature and high pressure fluid leakage, a second seal means locatedbetween the mating spherical surfaces on the other side of saidsupporting shaft means, whereby the first and second seal meanscooperate to form an effective seal to all high temperature and highpressure fluids.

2. The nozzle assembly as claimed in claim 1 wherein said first sealmeans comprises a metallic, piston-type seal ring and the second sealmeans comprises a nonmetallic O ring type seal.

3. A variable position nozzle assembly comprising; an annular bearinghousing having an internal surface which defines a first portion of aspherical cavity, an annular insert ring positioned within said annularhousing and having an internal surface defining a second portion of aspherical cavity, a lock ring securing said insert ring within saidannular housing, bearings located within said annular housing externalof said spherical cavity, two diametrically disposed apertures providingopenings between said bearings and said spherical cavity, aconvergentdivergent nozzle having a spherical external surface portionat one end, said spherical surface portion being positioned centrally ofsaid spherical cavity, a pair of support shafts journaled in saidbearings and extending radially inwardly through said apertures andconnected to said nozzle at said spherical surface portion, the diameterof the spherical surface portion provided by said insert ring beinggreater than that provided by said housing whereby unequal expansion ofthe various spherical surfaces is accommodated, and a pair of ringseals, one of which is positioned between said spherical surface of saidnozzle and the larger diametered portion of said cavity, and the otherof said seals being positioned between said spherical surface of saidnozzle and the smaller diametered portion of said cavity, wherebyleakage of fluid between said spherical surfaces is effectivelyeliminated.

(References on following page) 5 6 References Cited in the file of thispatent 2,829,909 Magnani Apr. 8, 195 8 TED A PAT T 2,846,242 Drake Aug.8, 1958 UNI ST TES EN S 2,849,860 Lowe Sept. 2, 1958 984,557 Gorter Feb.21, 1911 1,572,812 Rees Feb. 9, 1926 1,642,752 Landon Sept. 20, 1927 5FOREIGN PATENTS 2,098,188 Kinmont Nov. 2, 1937 841,231 France Feb. 1,1939 2,664,700 Benoit Jan. 5, 1954 370,803 France Dec. 22, 19442,758,851 Heath Aug. 14, 1956 1,022,847 Germany Jan. 16, 1958 2,780,059Fiedler Feb. 5, 1957 10 722,338 Great Britain Jan. 26, 1955 2,811,274Wilson Oct. 29, 1957 727,255 Great Britain Mar. 30, 1955

